A typical aircraft electrical power generation system (EPGS) includes a GCU configured to control the output voltage of an alternating-current (AC) electrical generator by means of an exciter drive.
As illustrated in FIG. 1, some versions of a GCU 100 may include a dual gate driver integrated circuit 102 that drives a two-switch, isolated exciter drive circuit 104 configured to energize a fixed exciter field winding (not shown). In normal operation, the two driver switches 106a-106b included in the dual gate driver circuit 102 operates 180 degrees out of phase with respect to one another during the on-time of the control pulse-width modulation (PWM) signal command used to regulate generator output voltage, while switching between a high voltage potential and a low voltage potential. The gate driver circuit 102 converts a first input voltage into a second higher output voltage. However, one of the two driver switches 106a-106b may experience a high rail fault or a low rail fault during which the faulty switch stays coupled to either the high voltage rail or the low voltage rail (see FIG. 2) as opposed to switching between the high voltage potential and the low voltage potential. This fault mode may remain dormant in the system and allow the generator to regulate output voltage properly, but cause additional stress in the exciter drive circuitry.